The proposed research is a 36 month plan to finish developing and evaluating a carbopol-based vaginal gel called BufferGel for its effect as a contraceptive and as a prophylactlc against the transmission of sexually transmitted diseases. The effect of BufferGel in vitro on sperm, HIV, HSV2, N. gonorrhea, and H. ducreyi will be determined, as well as its effect on vaginal flora. BufferGel will be tested for contraceptive efficacy in the rabbit model, chlamydia in the mouse model, and HSV2 in the mouse. BufferGel will also be evaluated for acute and chronic toxicity. An enhanced BufferGel containing Bufferspheres and/or additional polymers which maximize buffering capacity while retaining suitable consistency and retention will be developed and tested as above. The feasability of adding lactobacilli to both formulations will be explored.